Life & Style hears that Britney Spears is set to go on a custody attack against ex-husband Kevin Federline, believing K-Fed has been using marijuana in the presence of their two children Sean Preston and Jayden James. “She’s asked the court-appointed monitor and her lawyers if they can prove the kids have been exposed to environments in which drugs have been taken,” an insider said. The method would be a hair analysis, and if the kids test positive, the 26-year-old pop tart and her legal team intends to call an emergency hearing. An insider added, “Kevin could lose custody.” The full story at lifeandstylemag.com has since been removed.